In a large bowl, mix the flour, baking powder and salt. Add melted butter, combine well. Slowly add the warm water and mix until the dough comes together. Knead till you get a pliable dough. Add water slowly to ensure you don’t make the dough sticky.
Turn out the dough onto a lightly floured work surface, and knead for a few minutes until the dough comes out smooth and uniform. Divide the dough into 12 pieces, and form the dough into balls about the size of a large walnut. Allow the balls of dough to rest on a lightly floured surface, covered, for 15 minutes.
To shape the tortas fritas, flatten the ball of dough with your palm, and roll out a disc about 1/8 inch thick. Cut a small x in the center of the dough with a sharp knife.
Heat the cooking oil in a deep pan. The oil must be very hot to ensure quick frying and minimal absorption of grease. If the oil isn’t hot enough, the tortas fritas will turn out greasy and heavy.
Drop two to three pieces of dough into the hot cooking oil (depending on the size of the pan), and fry on one side until golden brown (approximately 45 to 60 seconds). With a pair of tongs, flip the tortas fritas over and continue frying on the other side until golden brown (roughly the same amount of time).
Remove the tortas fritas from the cooking oil and drain on paper towels. Sprinkle with sugar and serve hot.